What is more interesting to me than this fact is the question of why did all humans do this. What is the source of this in all ancient humans? I think there is a simple answer, but in that answer I still find ancient humans as resourceful as modern humans; they were just living at an earlier point in the path of acquired human knowledge. I think their brains - the physical instrument - were not working or wired much differently than ours, if at all.
In reality they simply passed it on from one pagan culture to another... and adapted, changed and or eliminated it to formulate whatever signs and symbols might be advantageous to their cultures and or tribes...taking various forms and meanings as it went.
Humans did this as they have a natural bent to worship something outside themself...with that comes a desire for order and leadership among them to accomodate that desire. Thus man will always make attempts at building dieties and/or pagan idols in which to carry out a sense of order in an otherwise and seemingly disordered world around them they cannot explain nor understand completely.
Human nature does not change over the centuries so of course the only thing which man can really change is the world they create around themselves....and all men see that which is around themselves thru the brain. It is thru the brain man might imagine or discover what he will. But despite what he might imagine there is a 'reality' in the world that is clear and precise...and able to be understood though always with limitations.
Not so much an acquired knowledge as it is discovery of what already is and realities of.